Las Vegas: Police swarmed the Las Vegas strip late Sunday following reports of multiple shots fired from the Mandalay Bay casino, media reports said. At least two people are killed and many are hospitalised with suspected gunshots wounds, a local hospital spokesman said.

"We're investigating reports of an active shooter near/around Mandalay Bay Casino," police said on Twitter. Several people including a police officer had been shot at a nearby outdoor concert, a local newspaper reported.

The video footage circulating on Twitter purportedly of the Mandalay Bay showed a crowd enjoying a concert before what sounds like volleys of automatic gunfire halt the performance.